This study will assess the significance of elevated basal and stimulated cortisol levels in HIV-infected children with regard to both the degree and level of coincident CNS dysfunction due to HIV itself. The degreee of HPA axis abnormality will be ascertained and related to specific anatomical lesions in the CNS. The investigators will attempt to determine if the abnormality of the HPA Axis occured prior to the occurence of specific HIV-related CNS dysfunction. The specific steroid pattern that is observed may be predictive of CNS dysfunction. Arthropomorphic measurements, neurological examination, MRI, 24 hr urine for cortisol, ACTH and CRF stimulation tests will be done at designated intervals.